1. Field of the Invention
The present invention relates to a backlight module, particularly one with a truss type structure.
2. Description of the Related Art
Liquid crystal display (LCD) TV has long become the mainstream of the market, and as a result, the sizes thereof are being made larger and larger. FIG. 1 shows a conventional backlight module used in an LCD panel. The backlight module 10 comprises a back cover 11, a reflector 12, a plurality of light sources 13, a plurality of optical films 16, a diffuser plate 14, and a front cover 15. The back cover 11, which provides most mechanical strength for the backlight module 10, is made of a metal such as aluminum or zinc-plated sheet steel (SECC). As the LCD panels are made larger, the back cover 11 and tooling therefor also have to be made larger and cost therefor is absolutely increased. In this case, the current manufacturing and equipment capability may not necessarily deal well with the newly introduced requirements. In addition, the increased dimension of the back cover 11 also means that the LCD panel (not shown) will become more weighted and the back cover 11 will suffer from the problem of insufficient bending strength.
In this regard, a reinforcing rib or a reinforcing plate (not shown) is generally suggested to increase the insufficient bending strength. However, mold cost is in this case further increased and such mold is in fact not easy to be fabricated. Moreover, the more weighted of such backlight module also imposes difficulties on transportation thereof and assembly therefor. In this case, further equipment has to be furnished and a further cost is required. Moreover, the weighty backlight module has to be charged with a pricy shipment cost.
Therefore, how to reduce the weight of an LCD backlight module without sacrificing its bending strength is an important issue for all LCD manufacturers.